we just need more information on what you got,,,,,,over 200 is too hot,,,,the bellypan diverts air UP towards the radiator,,,,AND,,,,,,basically,,,,if you aint movin,,,,you aint coolin,,,,,,but retarded timing will make the engine run hotter and cause dieseling,,,,so you need to check that,,,,,but people messed with these vans over the years, so you need to find out what you got,,,,,,if you hook the vacuum gauge to the intake manifold,,,,,at idle it should read about 17 inches of vacuum,,,,AND,,,twist the distributor a little either way and see what the highest reading you get on the gauge,,,,,get the highest you can while adjusting the RPMS , then the mixture,,, keep the RPMS to about 600,,,,,,look at the springs and weights under the rotor in the distributor,,,,,are the springs and weights tight,,,,when you twist the rotor,,,,does it snap back,,,,,now those harmonic balancers are a problem,,,,the pulley is mounted in rubber,,,,they do slip and then that notch ends up moving and lying to you,,,,just run some more tests,,,then you will get good answers instead of a 100 guesses......